Fin4713: Example: How much house can I afford? (Fixed amount for Property Tax and Insurance) You have a 50,000 annual income, and make car payments of 450 per month but have no other debt, and have $30000 in the bank. How much house can you afford, given the following mortgage opportunity: FRM conventional 30 year at 7.875%, requires 20% down with 28/36 qualifying ratio. Two discount points will be charges and closing cost and pro-rates =$3000. Property taxes will be 3600 per year and insurance 360 per year. Step 1. How much of loan do I qualify for? This depends on the PITI I am allowed 28% 1166.67 1166.67 1050 - 300 - 30 720 36% 1500 450 1050
Monthly income*ratio (50000/12*ratio) Less other debts Choose Min. as available for PITI Available for PITI = Less property taxes Less insurance Available for debt service (PI)
Max amount of loan you can service (use financial calculator or formula) = $99,300.84 Step 2: Compute maximum size of loan you can afford to close on. Savings = Other closing Funds available for points and down payment. 30000 3000 27000
Define the following notation: HV = house value LV = loan value For a 20% down payment loan note that 0.8*HV=LV or we can rewrite as HV = 1.25*LV In general for a down payment percent of "d" we can write (1-d)*HV = LV, or HV = [1/(1-d)]*LV We will allocate our available cash to either the down payment or the points so we can write: Cash = Down payment + loan point fee We know the Down payment depends on the HV and loan point fee on fee on the LV so we write: Cash = d*HV + p*LV where p = points, expressed as a fraction of loan We know the amount of cash we have, d, & p. We also know that HV=[1/(1-d)*LV) so we can write Cash = d*[1/(1-d)]*LV + p*LV or, solving for what we want to know, the LV we have: LV = Cash/[(d/(1-d) + p] For d=0.2 (i.e. 20% down payment) and p=0.02 (i.e. 2 points) and cash=27000 we have: LV=27000/[.2/(1-.2) + .02] = 27000/.27 = 100000 This is maximum size loan that we have funds to close on. We need to choose the lower of the two possible loan amounts; thus, the maximum size loan we can afford is $99,300. What is the maximum house we can afford? (Note that we don't need all of our cash to close this smaller loan, so we can use the extra money for a higher down payment (i.e. we are allowed more than 20% down, we are just not allow less) so we can apply that to buying the house. What remains is to compute the amount of house. Max house = Loan amount + cash − prepays − points = = 99300.84 + 30000 − 3000 − 1986.02 = $124,314.82